Rhinopneumonitis is a viral infection that primarily affects horses, caused by the equine herpesvirus (EHV). It leads to respiratory issues, including nasal discharge, coughing, and fever. The disease can spread easily among horses, especially in crowded environments like stables and racetracks. In addition to respiratory symptoms, rhinopneumonitis can also cause neurological problems and reproductive issues in pregnant mares. Vaccination is available to help prevent the disease, but it is not 100% effective. Good hygiene practices and isolation of infected animals are essential for controlling outbreaks.